<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>html标签head内定义style内部结合选择器CSS</title>
    <style>
        div{
            color: blue;
        }
    </style>
</head>
<body>
    <div>Hello CSS，键值冒,内部选择器定位</div>
</body>
</html>